Electrical idle detection and loss of signal (LOS) detection are common features in many high-speed serial interface protocols, such as the peripheral component interconnect express (PCIe) and serial advanced technology attachment (SATA) standards. These features are essential to the low-power high-speed serial interface designs because modern receivers use clock and data recovery (CDR) circuits and equalizers to process the received signals. In addition, it is important to know if there is valid signal presence in a link.